A longitudinal study of changes in body composition and basal metabolism in physically active elderly men.

Ageing in the elderly is usually characterised by loss of fat-free mass (FFM) and reduction in basal metabolic rate (BMR). These age-related changes probably vary in rate, timing and extent between subjects in response to differences in leisure or occupational physical activity, disease and several other factors. Information on rates of change in BMR and FFM is limited by study design (most published work is cross-sectional rather than longitudinal), and possibly by methodology (use of imprecise and/or biased methods for assessment of changes in body composition). In the present study BMR and body composition were first measured in 22 physically active elderly men (mean age 62) in good health and measurements were repeated 6.5 years later. Changes in BMR, FFM and percentage body fat were small and not statistically significant over the time period (paired t, P > 0.05). The study suggests that physically active elderly men in good health in this age range can show very small age-related declines in BMR and FFM.